20mm Dia., 0.5mm Thick, 2000-5000nm, High Durability AR Coated Sapphire Window

Product Details Achieves Severe Abrasion Requirements of MIL-C-675C Low Reflection Coatings for 400 – 1100nm or 2000 – 5000nm Ideal for Harsh Environments Requiring Thin Optics Uncoated Sapphire Windows are Also Available High Durability Anti-Reflection (AR) Coated Sapphire Windows are designed for applications requiring the ruggedness of sapphire with AR coatings designed to survive severe abrasion. The AR coatings on these sapphire windows are designed to withstand temperature cycling from -80 to +160°F, salt spray for a continuous period of 24 hours, and salt solubility for an immersion period of 24 hours. Coating designs achieving the severe abrasion requirements of MIL-C-675C for VIS-NIR and MWIR applications are available, making them ideal for use in harsh environments. High Durability Anti-Reflection (AR) Coated Sapphire Windows are used in aerospace, defense, and industrial applications, as well as any optical application requiring thin, durable protective windows. Specifications General Type: Protective Window Type of Window: Crystal Physical & Mechanical Properties Clear Aperture CA (mm): 18.00 Diameter (mm): 20.00 ±0.05 Thickness (mm): 0.50 ±0.05 Parallelism (arcmin): ≤3.5 Bevel: Protective as needed Clear Aperture (%): 90 Edges: Fine Ground Poisson’s Ratio: 0.27 Young’s Modulus (GPa): 435 Knoop Hardness (kg/mm 2 ): 1,900.00 Optical Properties Coating: Hardened BBAR (2000-5000nm) Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More Sapphire (Al 2 O 3 ) Index of Refraction (n d ): 1.77 Surface Quality: 80-50 Abbe Number (v d ): 72.24 Birefringence (n o -n e ): 0.008 for Visible Light Orthogonal to Optical Axis Axis Orientation: Random Coating Specification: R avg <1.5% @ 2000 - 5000nm R abs <2.0% @ 2000 - 5000nm Wavelength Range (nm): 2000 - 5000 Surface Flatness (P-V): 2λ (typical) Coating Temperature (°F): -80 to +160 per MIL-M-13508C Paragraph 4.4.4 Material Properties Density (g/cm 3 ): 3.97 Coefficient of Thermal Expansion CTE (10 -6 /°C): 8.8 Environmental & Durability Factors Coating Abrasion: Severe, per MIL-C-675C Paragraph 4.5.10 Coating Adhesion: Per MIL-M-13508C Paragraph 4.4.6 Coating Humidity: ≥24 Hours per MIL-C-675C paragraph 4.5.8 Coating Salt Spray: ≥24 Hours per MIL-C-675C paragraph 4.5.9 Coating Salt Solubility: ≥24 Hours Immersion per MIL-C-675C paragraph 4.5.7 Regulatory Compliance Certificate of Conformance: View ×